Team mate A chased Team Mate B in the first minute of the game and killed Team mate B with multiple shots. Team mate A turned blue. I feared Team mate A would do it again so I killed Team mate A to protect the team. I can't remember if I turned blue in game, but I did turn blue in the Garage.

Yes, you did do good. Teammates who are blue are either trolling TK'ers (How obvious) or... well thats it.
Killing blue guys doesnt give you a penalty and wont register the damage you did to him/her to the teamdamage system, so you're save.

Team mate A chased Team Mate B in the first minute of the game and killed Team mate B with multiple shots. Team mate A turned blue. I feared Team mate A would do it again so I killed Team mate A to protect the team. I can't remember if I turned blue in game, but I did turn blue in the Garage.

PS If the Smurfs are after me then there must be a Smurf embassy I can go to, to pay some kind of fine and get off their hit list. The last people I want to piss off are Smurfs, seriously those guys are loco.

PS If the Smurfs are after me then there must be a Smurf embassy I can go to, to pay some kind of fine and get off their hit list. The last people I want to piss off are Smurfs, seriously those guys are loco.

You did the right thing this time. But beware that sometimes people start the game with the blue colour or turn blue in game because they accidentaly kill some team mate (happens, sometimes light tanks die by simply touching you). So, you should always evaluate the situation before team killing a blue guy.

Team mate A chased Team Mate B in the first minute of the game and killed Team mate B with multiple shots. Team mate A turned blue. I feared Team mate A would do it again so I killed Team mate A to protect the team. I can't remember if I turned blue in game, but I did turn blue in the Garage.

Did I do the wrong thing?

How long will I remain blue?

What are the ongoing consequences?

Thank you in advance for you time.

There's no penalty for killing a blue player, but as suggested by others, you should wait and see if they continue their stupid behaviour before shooting. Every dead teammate, even blue ones, is a gun less in your favour.
Turning blue in the garage is just a warning that you have damaged an ally. Did the team kill happen in your cap circle maybe? Anyway, the colour disappears after a few games, if you're being a good boy.

Had a loltraktor game yesterday (platooned with new player who was just starting out) and two (un-platooned) T18s started killing tanks. I killed one, and the other was finished off by another T18, but not before they got 4 kills between them. So game 'began' with -6:0 score. I managed to get about 260 dmg and a kill, and another tank did about 60 dmg. Everyone else on team got nothing. was the worst case I've seen yet...

With the new patch, they at least get kicked from the game when they get banned.

You did good and the best thing was that you did evaluate the situation before shooting the blue guy.

It can happen rarely that peoples turn out blue even doing their best to support the team.

- Once a TigerII turned blue after killing me in my T50-2 our own cap circle. Wasn’t his fault. I was chasing another T50-2 that was after our arty and he did try help.

- Once I turned blue after killing a Panther in their cap circle with my Hummel. He was alone agains two IS and tried to save him by hitting the heavies. Like a miracle it passed over both the IS and ended up killing our panther instead. :/

But you were cool and evaluated the situation first so all the kudos for you. Hope to see you in game..